[Event "Interzonal-04"]
[Site "Portoroz"]
[Date "1958.09.03"]
[Round "17"]
[White "De Greif, Boris"]
[Black "Averbakh, Yuri L"]
[Result "1/2-1/2"]

1. c4 Nf6 2. Nf3 e6 3. Nc3 d5 4. d4 c5 5. cxd5 Nxd5 6. e3 Nc6 7. Bc4 Nxc3 8. bxc3 Be7 9. O-O O-O 10. Bd3 Bd7 11. Qe2 Rc8 12. Bb2 Qa5 13. Rfd1 Rfd8 14. Nd2 cxd4 15. exd4 Be8 16. Nc4 Qc7 17. a4 Nb8 18. Ba3 Bxa3 19. Rxa3 Nd7 20. a5 Nf6 21. Rb1 Rd5 22. a6 b6 23. Ne5 Rdd8 24. Qb2 Nd7 25. Nxd7 Rxd7 26. Bf1 Rcd8 27. Re1 Rd6 28. Raa1 Bc6 29. Re3 Qe7 30. Rae1 Qf6 31. Re5 Rd5 32. Qc1 Rxe5 33. Rxe5 Rd5 34. Rxd5 exd5 35. Qe3 Qd6 36. g3 g6 37. h4 h5 38. Kh2 Bd7 39. Be2 Qe6 40. Qd2 Qe4 41. Bf1 Bf5 42. Bg2 Qd3 43. Qf4 Qxa6 44. Bxd5 Qe2 45. c4 1/2-1/2